Pump for injection engines



Aug. 17,1943. R. MARAIS I 2,326,958

PUMP FOR INJEcTIoN ENGINES Filed Nov. 20,519.39 4 Sheets-Sheet 1 Aug. 17, 1943. R. MARAIS I 2,326,953

1 PUMPFOR INJECTION ENGINES Filed Nov. 20, 1959 4 Sheets-Sheet 2 Aug. 17, 1-943.

R. MARAVIS PUMP FOR INJECTION ENGINES Fiied Nov. 20, 1939 4 Sheets-Sheet 4 Patented Aug. 17, 1943 UNITED STATES "PATENT OFFICE,

I rum non liaison ENGINES I I Ren Marais, Paris, France; vested in the Alien Property Application November 20, 1939, Serial No.'305,384 In France November 23, 1938 I .5 Claims- (Cl. 103-154) In the feeding of engines of the Diesel type and in order to obtain a satisfactory injection it is necessary that the size of the fuel conduits should be as reduced as possibleyparticularly those in which the fuelis subjected to the injection pressure. I

The present invention has for object a fuel pump for iniectionengines in which each elementary pump feeds two cylinders of the engine,

the piston of eachpump moving with it a distributing member which directs its delivery alternately on two cylinders of the engine; the cylinder of each pump is arranged parallel to the I cylinder of another pump and in opposed relationship, 'that isto say, the head of the-cylinder 'of one pump is arranged adjacent the head of the cylinder of the adjacent pump.

of the volumes of the conduits wherein the liquid.

fuel is subjected to the injection pressure,

A form of construction of a pump thus devised having two cylinders for feeding a four-cylinder injection engine, is illustrated by way or non limiting example, in the accompanying diagrammatic drawings, wherein Fig. 1 is an elevation thereof.

Fig. 2 is a top plan view in section through the I axis of the pump bodies.

Fig. 3 is a side view.

Figs. 4 to llillustrate the development of the profile of the control cams for the pistons with.

relationto the position of the pistons wherein flees 61,62 and it is delivered, through valves such 01, ca (Fig. 4) for instance, in variable quantity according to the orientation given to the pistons bi b: by means of the rack h and the pinions hi, ha. The pinions hi, ha are fixed on sleeves z journalled about'the pump cylinders a1 and as, and extending therebeyond, the outer ends of the sleeves 2 being slotted as at 21 for engagement 'with the adjacent ears 2: situated on the periph cry of milled discsza in turn carried by the respective pistons b1 and be. It will thus be seen that when the pinions are rotated the pistons will I also be rotated. The heads of the pistons include a known system of grooves U1, 1):, and inclines s which, according to the longitudinal position and the orientation of the piston determine the instant and duration of the communication of the fuel inlet orifices e1 and er with the chambers t1 and t: of the cylinders at the head of the piston. The springsii and i: hold the pistons pressed against the control earns 01 c: through the medium Figs. 4, 6, 8 and 10 shows the positions at the beginning of the injection and Figs. 5, 7, 9 and ,11 show the positions at the end of the injection.

Figs. 12 and 13 are modified arrangements of the delivery valves.

Fig. 14 is a section of one of the pistons taken online:czofFlg.2.

of rollers.

A part of each piston In or in forms a distributing slide-valve and isprovided for that purpose with a recess 11 or a: of suitable length, whereas the corresponding pump body comprises three ports: an inlet port In or k: and two outlet ports am or m2, m or m, said outlet ports being respec tively connected to the cylinders 2, 4, 3, I of the engine.

The control cam c1 comprises two bosses (Figs.

4 to 11) one serving 'to impart to the piston in a delivery stroke immediately followed by a rapid return, the other imparting to the same piston a. delivery movement followed by a rest at the end of the stroke during about 60, then by a return stroke. The cam ca has a similar profile but is offset to the extent of a quarter of revolution with relation to the cam or.

In this way each piston hi or b: is moved by a I cam 01 or or having two bosses one of which causes its return after the deliveryof the fuel towards the distributor of the qaposed pump and the other 7 retaining said piston lifted during one of the de- Fig. 15 is an elevation similar to Fig. 1, showing a modification of the control for the pump pistns I a1 and a: designate the two cylinders or pump bodies, in and b: the corresponding pistons, c1 and c: the cams secured on the shaft 0 which rc- The fuel is tates at half the speed of the engine.

liveryperiods of pistonof theother or of another elementary pump. v

Figs. 4 to -11 show the various positions of the pistons ensuring successively and alternatively the function of the pump and of the distributor. Thus it will be seen that in Fig. 4 the piston b2 delivers from' the chamber ta of itscylinder through the valve 0: and chamber is in which the part 11 of the piston forms a distributor toward the supply conduit m1 of one of the cylinders .of admitted through a conduit d to the suction ori the engine. I In Fig. 6 it is the piston in which delivers from chaber t1 0! its cylinder, through the valve 111 and chamber ii in which the part a:

n-ofpiston b2 forms the distributor,'toward the conduit m of another cylinder of the engine. Further developments are apparent from an inspec- 7 tion or the other figures of the drawings.

The cylinders 01 and a: are arranged parallel to each other and in opposed relationship, that is to say, the head of one cylinder is adjacent tothe head of theother, so that the conduits p1 and p:

can be as short as possible. A considerable reduction of the volumes of the conduits in which the fuel is subjected to injection pressure, is thereby obtained moreover, the arrangement oi. the pump cylinders two by two contiguous at their heads permits the construction of a two cylinder pump for a four-cylinder engine with the reduced bulk illustrated in the drawings.

The movements of the piston would be the same 0 as in the previous instance.

The delivery valves can be arranged in various manners diagrammatically illustrated in the form of ball valves in Figs. 4 to 11, on the one hand, and, on the other hand, in Figs. 12 and 13. Their operation, in all cases, need not be explained.

I claim: Y

1. In a pumping and distributing apparatus, the combination or a first piston pump and a first distributor actuated by the piston or said first pump, a second piston pump substantially parallel to the first one and set in a direction reverse to that of the first pump and a second distributor actuated by the piston of saidsecondpump, the first distributor being placed in proximity to the second pump and the, second distributor being placed in proximity to the first pump, and means for connecting the first distributor to the delivery or the second pump and for connecting the second distributor tothe delivery of the first pump.

2. In a pumping and distributing apparatus,

' the combination of a first piston pump and a first distributor having a slide-valve actuated by the piston of said first pump, a second piston pump substantially parallel to the first one and set in a direction reverse to that of the first pump and a second distributor having a slide-valve actuated by the piston of said second pump, the. first dis-- tributor being placed in proximity to the second pump and the second distributor being placed in proximity to the first pump, a rectilinear pipe for connecting the first'distributor to the delivery or the second pump, and a rectilinear pipe for connecting the second distributor to the delivery of the first pump.

3. In a pumping and distributing apparatus, the combination or a first piston pump and a first distributor having a slide-valve actuated by the piston or said first pump, a second piston pump respectively, one of the pistons substantially parallel to the first one and set in a direction reverse to that or the first pump and a second distributor having a slide-valve actuated by the piston of said second pump, the first distributor being placed in proximity to the second pump and the second distributor being placed in proximity to the first-pump, a rectilinear pipe of short length for connecting the first distributor to the delivery of the second pump, a rectilinear pipe of short length for connecting the second distributor to the delivery of the first pump, and check valves in said pipes.

4. In a pumping and distributing apparatus,

. the combination or a first piston pump with a de livery orifice and a first distributor having a cylinder and cylindrical slide-valve in said cylinder actuated by the piston oi! said first pump with an admission orifice and at least one delivery orifice in said cylinder of said first distributor, a second piston pump with a delivery orifice substantially parallel to the first one and set in a direction reverse to that of the first pump and a second distributor having a cylinder and a cylindrical slidevalve in said cylinder, actuated by the piston of said second pump, with an admission orifice and at least one delivery orifice in said cylinder of 'said second distributor, the first distributor being placed in proximity to the second pump with its admission orifice placed opposite the delivery orifice of said second pump, and the second distributor being placed in proximity to the first pump with its admission orifice placed opposite the delivery orifice of said first pump, a rectilinear pipe of short length for connecting the admission orifice or the firstdistributor to the delivery orifice of the second pump, a rectilinear pipe of short length for connecting the admission orifice or the second distributor to the delivery orifice oi the first pump, and check valves in said pipes.

5. In a pumping and distributing apparatus; the combination of a first pump cylinder bored in a pump body with an admission orifice and a delivery orifice and a first distributingcylinder bored in said pump body in the extension of the first pump-cylinder with an admission orifice and at least one delivery orifice, a second pump cylinder bored in said same pump body parallel to the first pump cylinder and in a direction reverse to that of said first pump cylinder with an admission orifice and a delivery orifice. and a second distributing cylinder bored in said pump body in the extension of the first pump cylinder with an admission orifice and at least onedelivery orifice, a pumping piston in each pump cylinder, a cylindrical slide-valve in each of said distributin cylinders and connected to the corresponding pumping piston, the first distributing cylinder being placed in Proximity-to the second pu p cylinder and the second distributing cylinder being placed in proximity to the first Dump cy der, a rectilinear pipe bored in said pump body for connecting the admission orifice oi the first distributing cylinder to the delivery orifice 0f the second pump cylinder, a rectilinear pipe bored in said pump body for connecting the admission orifice of the second distributing cylinder to the' delivery orifice of the first pump cylinder, and 

